Model specification: model: ordinary type, reinforced type: 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, O.o, o. The structure of ao7.0,. 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0 is composed of....... The common type consists of endotracheal tube body, inflatable tube, cuff, joint, inflation valve and guide core (optional). The reinforced type consists of endotracheal tube with steel wire tube body, inflatable tube, cuff, joint, inflation valve and guide core. Scope of application: for the establishment of artificial airway in clinical anesthesia or emergency.